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Intrauterine Device (IUD)

What is an intrauterine device (IUD)?

The intrauterine device (IUD), previously also called a coil or loop, is a birth control device placed into a woman's uterus by a health care provider. It is usually made of plastic or metal with a string attached. There are 2 types of IUDs. The devices that contain copper can stay in the uterus for up to 10 years. IUDs that contain the female hormone progesterone can stay in place up to 5 years.

The IUD prevents pregnancy by changing the physical environment of the reproductive tract. These changes appear to prevent the egg from being fertilized or implanting and growing in the uterus.

There has been some controversy over the use of the IUD because of its association with pelvic infections. Talk to your health care provider about the risks of using an IUD if you have had any of the following problems:

  • heavy menstrual bleeding
  • an infection in any of your reproductive organs (ovaries, uterus, fallopian tubes)
  • pregnancy in a fallopian tube (ectopic pregnancy).

How is it used?

Your health care provider will insert the IUD into the uterus through the vagina and cervix (opening of the uterus). The IUD is usually inserted during a menstrual period, when the cervix is slightly open and you are least likely to be pregnant. It takes only a few minutes to insert an IUD. You may feel some cramping pain when the IUD is being inserted. You may be given a local anesthetic or pain medicine before the IUD is inserted to help control this discomfort.

Your health care provider may examine you after your next menstrual period to be sure the IUD is staying in the right place. During the first few months after insertion of an IUD, check often for the attached string to be sure that the IUD is still in the uterus. You should also check for the string after every menstrual period. You can do this by putting a finger inside the vagina and feeling for the string near the cervix. (Be careful not to pull on the string.) As long as you can feel the string, the IUD is in position and it is unlikely that you will become pregnant. If you feel the hard plastic of the IUD, it is no longer in the correct place and you will have to see your health care provider to change it.

The IUD could come out accidentally in the first few months, possibly without being noticed. Always check the IUD before you have intercourse. You might want to use a backup method of birth control during the first few months, just to be safe.

You may be able to have an IUD from 5 to 10 years before it needs to be replaced. Usually progesterone IUDs are replaced after 5 years. Copper IUDs must be replaced after 10 years.

The copper IUD can also be used for emergency birth control. It can be inserted up to 5 days after unprotected intercourse. Studies have shown it to prevent pregnancy 99.9% of the time when it is used in this way. The IUD can then be left in place for up to 10 years.

You should not use a copper IUD if you are allergic to copper or metals.

Tell your health care provider if you or your partner have more than 1 sexual partner. Your risk of developing pelvic inflammatory disease is higher if you have more than 1 sexual partner, especially while you have an IUD in place.

What are the benefits?

The benefits of an IUD are:

  • It is 99% effective as a method of preventing pregnancy.
  • It does not cost much.
  • Lovemaking does not need to be interrupted by the insertion of a birth control device or spermicide.
  • Replacement is required just every 5 to 10 years, depending on the type.
  • The progesterone-containing IUD decreases the amount of bleeding and cramps that you have during your periods. (Sometimes you may skip menstrual periods with this type of IUD.)
  • Unlike birth control pills, it starts preventing pregnancy as soon as you start using it, and it is safe to use while you are breast-feeding.

Women do not have a harder time getting pregnant after removal of an IUD than they do after the use of other forms of birth control.

What are the risks?

A number of problems could occur while you are using an IUD, some of which can be severe. These problems are listed below (the first two are the most common):

  • increased menstrual bleeding and cramps, mostly during the first few months of use
  • spotting between menstrual periods
  • irritation of your partner's penis
  • increased risk of pelvic inflammatory disease, which can lead to infertility
  • unnoticed loss of the IUD from the uterus, which may result in unexpected pregnancy
  • embedding of the IUD in the uterine wall
  • damage to the uterus by the IUD, with possible damage to other organs as well as internal bleeding
  • potential problems if pregnancy occurs with an IUD in place, including ectopic (tubal) pregnancy.

If you become pregnant with an IUD in place, it should be removed right away. It might increase your risk of miscarriage (loss of the baby), as well as the risk of infection in the uterus and preterm birth of the baby.

Do not receive diathermy (deep heat) treatments if you have a copper IUD. Diathermy treatment increases the risk of injury to the tissues of the uterus.

IUDs do not protect against sexually transmitted diseases, such as AIDS. Use latex or polyurethane condoms for protection against these infections.

There has been no evidence of birth defects resulting from the use of an IUD.

Who should not use an IUD?

You should not use an IUD if:

  • You have cancer in the uterus or cervix.
  • You have unexplained vaginal bleeding.
  • You may be pregnant.
  • You have had pelvic inflammatory disease.
  • You have a severe infection of the cervix (cervicitis).
  • You have fibroids or other problems with the structure of the uterus that make it hard to insert the IUD.

When should I call my health care provider?

Call your provider if you:

  • Cannot find the IUD string or you feel the hard plastic of the IUD.
  • Have vaginal discharge with a bad odor.
  • Have severe, unexpected pain in your lower abdomen, especially if it happens when you have intercourse.
  • Have heavy bleeding for more than 1 menstrual period.
  • Have a fever with no apparent cause.
  • Missed a period.
  • Think you might be pregnant with the IUD still inside the uterus.
  • Want to have the IUD removed.
Developed by Phyllis G. Cooper, RN, MN, and McKesson Provider Technologies.
Published by McKesson Provider Technologies.
Last modified: 2006-11-16
Last reviewed: 2006-09-22
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
Copyright 2006 McKesson Corporation and/or one of its subsidiaries. All Rights Reserved.
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